Fork lift-loader attachment for mobile lifting vehicles



Jan. 29, 1963 K. N. KNUTSON 3,

FORK LIFT-LOADER ATTACHMENT FOR MOBILE LIFTING VEHICLES Filed Dec. 7. 1959 HHIHI I iE I T w T T F KelsggN. Knu fson INVENTOR.

United States Patent Ofifice dfi'fifidl Patented Jan. 2%, 1953 3,075,661 FGRK LlFT-LOADER ATTACHPVEENT Fill-R MQBTLE LlFTlNG VEHl CLES Kelsey N. Knutson, 1044 NE. Dean, Portland, Ureg. Filed Dec. 7, 1959, Ser. No. 857,974 2 Claims. ((13. 214-140) This invention relates to fork lift-loader attachments for mobile lifting vehicles. it pertains particularly to fork attachments for application to the blades of bulldozers.

In logging operations, it is common practice to transport the logs from the woods to a central station where they are loaded on a truck. The loading is accomplished by various methods, usually relying upon the application of a hoist or derrick.

It is a general object of the present invention to provide apparatus for transporting and loading logs rapidly and efficiently and without the necessity of using a special derrick for the purpose.

It is another particular object of the present invention to provide a fork attachment which may be releasably secured to the blade of a bulldozer, making the same useful in a variety of transporting and loading applications.

Still another object of the present invention is the provision of a fork attachment for a bulldozer blade which is simple in construction and easily attached to and detached from the blade.

The manner in which the foregoing and other objects of this invention are accomplished will be apparent from the accompanying specification and claims considered together with the drawings, wherein like numerals of reference indicate like parts and wherein:

FIG. 1 is a view in side elevation of a bulldozer equipped with the herein described fork lift-loader attachment and being used in loading logs on a logging truck;

FIGS. 2 and 3 are side and rear elevations respectively of the herein described attachment;

FIG. 4 is a vertical sectional view taken along line 4-4 of PEG. 3; and

FIG' 5 is a top plan view of the attachment looking in the direction of arrows 55 of FIG. 2.

Generally stated, the fork lift-loader attachment of my invention comprises a fork and pivotal mounting means for pivotally mounting the fork on the lifting member of a mobile lifting vehicle, for example, on the blade of a bulldozer. Latch means are provided on the fork which are trippable by contact with a stationary member, thereby shifting the fork from an elevated load-carrying position to a lowered load-discharging position. Thus the fork may be applied to a diversity of operations including especially the loading of logs on logging trucks.

Considering the foregoing in greater detail and with particular reference to the drawings:

The herein described attachment is designed for use with a variety of mobile vehicles but is particularly applicable to a conventional bulldozer H equipped with a blade 12 which may be lifted and shifted in the usual manner by means of cylinders 14-, 16.

The attachment normally is used in pairs, each member of which includes a vertical, channel-shaped support member 20. The inner face of the support member is contoured to conform generally to the contour of the outer face of the bulldozer blade.

Attaching means are provided for releaseably attaching the support member to the blade. In the illustrated form of the invention such attaching means comprise a lower pair of dogs or hooks 22. and an upper dog or hook 24.

In the illustrated form of the invention the lower dogs are stationary, being formed integrally with the side walls of support member 26. They are adapted to engage the lower edge of the blade.

The upper dog 24, however, is adjustable and accord ingly is mounted in a unit the construction of which is particularly apparent in FIGS. 3-5.

Thus the inner, upper side faces of support member 20 are provided with parallel pads 25, the lower margins of which are recessed. An eye bolt 26 is mounted between the pads. The eye of the bolt receives a pin 28 which seats in the recesses in the lower ends of pads 25, thereby anchoring the lower end of the bolt. Dog 24 is slidably mounted on the threaded section of the eye bolt and secured by means of washer 3d and nut 32.

Accordingly all that is required to mount the support on the bulldozer blade is to engage dogs 22 with the lower edge thereof, slip eye bolt 26 into position in the upper end of the support with dog 24 engaging the upper edge of the blade, and tighten bolt 32 until Washer 30 bears firmly against the tops of pads 25.

A fork member 36 is pivotally connected to the lower end of support member 2th by means of pin 38. It may be of substantial construction and extends forwardly of the blade at distance sufiicient to make it insertable beneath the log or other object to be carried.

Latch means are present for releasably securing the fork in its load-carrying position. The construction of the latch is illustrated in FIGS. 3 and 4.

Although various types of latches may be employed, the illustrated latch comprises an angular stepped lever 40, one end of which is pivoted between the sides of support member 29 by means of pin 42. The other end extends freely rearwardly outside the housing provided by support 2.0 and substantially aligned with fork 36 below the plane of the bulldozer blade. The stepped section of lever 49 mounts a roller 44- which bears against the flattened upper surface of the shank end of pivoted fork 36.

Accordingly, when lever it? is in the position of 'FIG. 4, it secures the fork in its load-carrying, operative position. However, if the outwardly extending free end of the lever is moved upwardly, roller 4% rolls freely across the upper surface of the fork shank until the latter is disengaged whereupon the fork is released and drops to a load-discharging position.

This manner of functioning lends the greatest utility to the herein described attachment. As indicated in FIG. 1, the log loading site may be provided with an elevated lramp ld along the brow of which is positioned a dry The roadway 5% lies at a level which is somewhat lower than that of the ramp so that the bed of log truck 52. is substantially level with the ramp. Truck 59 is of the conventional construction, being provided with a log bunk 5d and stake 56.

In operation the bulldozer picks up a log at a distant location with its forks. It then carries the log along ramp 46 until it has reached the position of FIG. 1. The blade then may be lowered until the free end of lever 40 contacts dry log 48. This trips the latch and permits fork 36 to drop down to the dotted line position of FIG. 1. The log then will roll off the fork and on to the truck bed until it comes to rest against stake 56.

This operation may be repeated until the first tier of logs on the truck has been completed. The second tier then may be loaded in similar fashion using the previously loaded first tier logs to trip the latch. Thus the entire truck may be loaded rapidly and without the use of special equipment other than the herein described detachable fork attachment.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to 3 without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. The fork lift-loader attachment comprising a fork, pivotal mounting means for pivotally mounting the fork adjacent the lower end of a lifting member of a mobile lifting vehicle, and latch means on the fork, the latch means being trippable upon downward movement thereof with a lifting member and contact with a stationary object to release the fork from an elevated load-carrying position to a lowered, load-discharging position.

2. A fork lift-loader attachment for bulldozer blades comprising a support, securing means for securing the support to a bulldozer blade, fork means pivotally mounted on the support adjacent the bottom of the latter and extending forwardly from the lower end of a bulldozer blade, and latch means mounted adjacent the bottom of the support, said latch means comprising a stepped angular lever mounting a roller on its stepped section, one end of the lever being pivoted to the support and the other extending Reterenees tilted in the file of this patent UNlTED SIAIES PATENTS 704,345 Kindsvater July 8, 1902 1,359,841 Russell Nov. 23, 1920 1,799,710 Strom Apr. 7, 1931 2,4735% rock June 21, 1949 2,515,384 Von Carnop July 18, 1950 2,876,584 Smith Mar. 10, 1959 

1. THE FORK LIFT-LOADER ATTACHMENT COMPRISING A FORK, PIVOTAL MOUNTING MEANS FOR PIVOTALLY MOUNTING THE FORK ADJACENT THE LOWER END OF A LIFTING MEMBER OF A MOBILE LIFTING VEHICLE, AND LATCH MEANS ON THE FORK, THE LATCH MEANS BEING TRIPPABLE UPON DOWNWARD MOVEMENT THEREOF WITH A LIFTING MEMBER AND CONTACT WITH A STATIONARY OBJECT TO RELEASE THE FORK FROM AN ELEVATED LOAD-CARRYING POSITION TO A LOWERED, LOAD-DISCHARGING POSITION. 